ASAI Masamitsu

Department of Computational Systems BiologyProfessor

Last Updated :2024/06/18

■Researcher basic information

Degree

  • PH.D.(1992/03 Osaka Prefecture University)

Research Keyword

  • space solar power systems   inverse dam   metamaterials   quasi-isotropic particles   matrix-eigenvalue method   Structural colouring   Shadow theory   カーボンマイクロコイル   chiral medium   diffraction gratings   電磁波   metamaterial   chiral   grating   diffraction   scattering   Electromagnetic wave   

Research Field

  • Natural sciences / Mathematical physics and basic theory / Electromagnetics
  • Nanotechnology/Materials / Applied physics - general

■Career

Career

  • 2021/07 - Today  Marine Inverse Dam Societymanaging director
  • 2008 - Today  Kindai UniversityFaculty of Biology-Oriented Science and TechnologyProfessor
  • 2008 - Today  Kyoto UniversityVisiting Lecturer
  • 2021/01 - 2021/06  Marine Inverse Dam Societyexecutive director
  • 2019 - 2021  Wakayama UniversityVisiting Lecturer
  • 2011 - 2019  Japan Helical Science Societyexecutive director
  • 2015 - 2018  Library of Faculty of Biology-Oriented Science and Technology, Kindai UniversityDirector
  • 2011 - 2018  Radiation Science Society of JapanExecutive Director
  • 2003 - 2008  Kindai UniversityFaculty of Biology-Oriented Science and TechnologyAssociate Professor
  • 1997 - 2003  Kindai UniversityFaculty of Biology-Oriented Science and Technology, Department of Electronic Systems and Information EngineeringRsearch Assistant
  • 1997 - 1998  University of UtahVisiting Faculty
  • 1993 - 1996  Kindai UniversityFaculty of Biology-Oriented Science and Technology, Department of Electronic Systems and Information EngineeringResearch Associate
  • 1992 - 1993  Kindai UniversityFaculty of Science and EngineeringResearch Associate

Educational Background

  • 1989/04 - 1992/03  Osaka Prefecture University  Graduate School of Engineering  Ph. D Course
  • 1987/04 - 1989/03  Osaka Prefecture University  Graduate School of Engineering  Master's Course
  • 1982/04 - 1987/03  Osaka Prefecture University  College of Engineering  Department of Electrical Engineering
  • 1978/04 - 1981/03  Aiko High School

Member History

  • 2021/07 - Today   The Marine Inverse Dam Society   Executive director
  • 2021/01 - Today   KID-S Microwave Technical Committee   chairman
  • 2019 - Today   Optical Society of America   "Optical Express", Reviewer
  • 2018 - Today   Radiation Science Society of Japan   Chairman
  • 2016 - Today   IEEE Nanotechnology Society   "IEEE Transactions on Nanotechnology", Reviewer
  • 2001 - Today   The Japan Society of Applied physics   "Applied Physics Express", Reviewer
  • 2001 - Today   The Japan Society of Applied Physics   "Japanese Journal of Applied Physics", Reviewer
  • 2001 - Today   IEEE Microwave Theory & Techniques Society   "IEEE Transactions on Microwave Theory & Techniques", Reviewer
  • 2021/01 -2021/06   The Marine Inverse Dam Society   Standing director
  • 2019 -2020   CMC Advanced R&D Laboratories Advisory committtee   Committee member
  • 2011 -2019   Japan Helical Science Society   Director
  • 2015 -2018   Iwade City Library Council   Chairman
  • 2011 -2018   Radiation Science Society of Japan   Executive director
  • 2016 -2016   Wakayama Library Council   Chairman
  • 2009 -2011   International Institute for Advanced Studies   Member of the Research Project Committee

■Research activity information

Award

  • 2023/09 AIE (Advances in Engineering) Key Scientific Article Certificate
     
    受賞者: Masamitsu Asai
  • 2013 2013 JSST International Conference on Simulation Technology Outstanding Presentation Award
     
    受賞者: Masamitsu Asai
  • 1996 The Institute of Electrical Engineers of Japan IEEJ Symposium Distinguished Paper Award
     JPN 
    受賞者: ASAI Masamitsu

Paper

  • Hideaki Wakabayashi; Masamitsu Asai; Jiro Yamakita
    Journal of the Optical Society of America A Optica Publishing Group 40 (2) 305 - 305 1084-7529 2023/02 
    In the shadow theory, a new description of electromagnetic fields using scattering factors has been employed. This paper presents a new numerical method based on scattering factors for the scattering problem of a composite dielectric grating embedded with conducting strips. The scattering factors for the primary fields, which are based on the assumption of conducting strips being removed completely and those for the secondary fields generated by the surface electric currents on conducting strips, are introduced. The presented method is formulated to obtain scattering factors for the total fields and Joule losses for propagating wave and evanescent wave incidences from the currents determined by using the Galerkin procedure. Numerical examples are given for an asymmetric multiple plane grating consisting of conducting strips. The scattering properties and the normalized Joule losses are calculated for propagating wave and evanescent wave incidences. It is shown that the diffraction efficiencies and scattering factors hold the symmetries on the reciprocity in the case of resistive plane gratings.
  • On the regular tetrahedral layout of helices for a quasi-isotropic chiral particle
    Masamitsu Asai; Hideaki Wakabayashi; Jiro Yamakita
    Proceedings of International Conference on Simulation Technology 1 (1) 2021/09 [Refereed]
  • Application of multilayered division method to scattering by slanted gratings
    Hideaki Wakabayashi; Masamitsu Asai; Jiro Yamakita
    Proceedings of International Conference on Simulation Technology 1 (1) 2021/09 [Refereed]
  • Hideaki Wakabayashi; Masamitsu Asai; Jiro Yamakita
    Journal of the Optical Society of America A The Optical Society 37 (10) 1539 - 1547 1084-7529 2020/08 [Refereed]
  • Structural coloration by slanted subwavelength gratings in conical mounting
    Hideaki Wakabayashi; Masamitsu Asai; Jiro Yamakita
    Proceedings of International Conference on Simulation Technology 2019/11 [Refereed]
  • Cubic arrangement of helices as a particle for a quasi-Isotropic chiral medium
    Masamitsu Asai; Hideaki Wakabayashi; Jiro Yamakita
    Proceedings of International Conference on Simulation Technology 2019/11 [Refereed]
  • Hideaki Wakabayashi; Masamitsu Asai; Jiro Yamakita
    Journal of the Optical Society of America A The Optical Society 35 (11) 1861 - 1870 1084-7529 2018/11 [Refereed]
  • Numerical Analysis for Structural Coloration in Multilayered Dielectric Gratings
    Hideaki Wakabayashi; Masamitsu Asai; Jiro Yamakita
    Proceedings of Progress in Electromagnetics Research Symposium 2018/07 [Refereed]
  • Accuracy evaluation on numerical analysis of scattering fields by dielectric gratings in terms of reciprocity theorem
    Hideaki Wakabayashi; Masamitsu Asai; Jiro Yamakita
    Proceedings of Progress in Electromagnetics Research Symposium 2018/07 [Refereed]
  • On the accuracy of the MoM analysis for the scattering factors of metallic strip gratings with dielectric slabs in terms of the reciprocity theorem
    Masamitsu Asai; Hideaki Wakabayashi; Jiro Yamakita
    Proceedings of International Conference on Simulation Technology OS2 (21) 2017/10 [Refereed]
  • Reciprocity Error of Numerical Solutions in Dielectric Gratings
    Hideaki Wakabayashi; Masamitsu Asai; Jiro Yamakita
    Proceedings of International Conference on Simulation Technology OS2 (20) 2017/10 [Refereed]
  • Hideaki Wakabayashi; Masamitsu Asai; Jiro Yamakita
    2017 IEEE INTERNATIONAL CONFERENCE ON COMPUTATIONAL ELECTROMAGNETICS (ICCEM) IEEE 3C1.3 300 - 302 2017 [Refereed]
     
    In the theory of gratings, a numerical diffraction solution must be satisfy the energy balance and the reciprocity. The matrix eigenvalues method has been presented to study the diffraction by dielectric gratings. In the method, the error of energy balance always becomes zero except for rounding error. An accuracy criterion of a solution is left as a difficult problem. This paper shows the reciprocity for the diffraction efficiencies of the reflected and transmitted waves, numerically. It is suggested that the reciprocity can be used the criterion.
  • Hideaki Wakabayashi; Masamitsu Asai; Keiji Matsumoto; Jiro Yamakita
    JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION OPTICAL SOC AMER 33 (11) 2188 - 2197 1084-7529 2016/11 [Refereed]
     
    Nakayama's shadow theory first discussed the diffraction by a perfectly conducting grating in a planar mounting. In the theory, a new formulation by use of a scattering factor was proposed. This paper focuses on the middle regions of a multilayered dielectric grating placed in conical mounting. Applying the shadow theory to the matrix eigenvalues method, we compose new transformation and improved propagation matrices of the shadow theory for conical mounting. Using these matrices and scattering factors, being the basic quantity of diffraction amplitudes, we formulate a new description of three-dimensional scattering fields which is available even for cases where the eigenvalues are degenerate in any region. Some numerical examples are given for cases where the eigenvalues are degenerate in the middle regions. (C) 2016 Optical Society of America
  • Numerical Analysis for Structural Coloration of Multilayered Gratings of Non-ideal Type
    Hideaki Wakabayashi; Masamitsu Asai; Jiro Yamakita
    Proceedings of International Conference on Simulation Technology 1 2016/10 [Refereed]
  • Masamitsu Asai; Hideaki Wakabayashi; Jiro Yamakita
    2016 INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (ISAP) IEEE 1 182 - 183 2016 [Refereed]
     
    Effective constitutive characteristics of three-dimensional periodic array of quasi-isotropic chiral particles composed of thin-wire twisted staples are analyzed. The Lorentz' approach is applied with the method of moments to evaluate the isotropy of the resultant medium. The cancellation of electric quadrupole moments is also checked for evaluation.
  • Numerical study on small quasi-isotropic particles for chiral media with fine granularity
    Masamitsu Asai; Hideaki Wakabayashi; Jiro Yamakita
    Proceedings of International Conference on Simulation Technology 1 2015/10 [Refereed]
  • Three dimensional analysis of structural coloration in subwavelength gratings
    Hideaki Wakabayashi; Masamitsu Asai; Jiro Yamakita
    Proceedings of International Conference on Simulation Technology 1 2015/10 [Refereed]
  • Hideaki Wakabayashi; Masamitsu Asai; Jiro Yamakita
    IEICE TRANSACTIONS ON ELECTRONICS IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG E98C (2) 162 - 165 1745-1353 2015/02 [Refereed]
     
    In the scattering problem of dielectric gratings in conical mounting, we have considered and formulated scattering fields using transverse electric (TE) and transverse magnetic (TM) waves. This paper formulates scattering fields by superpositions of right-circularly (RC) and left-circularly (LC) polarized waves through the matrix eigenvalue method.
  • Periodic array of thin-wire chiral objects with cancellation of quadrupole moments
    Masamitsu Asai; Hideaki Wakabayashi; Keiji Matsumoto; Jiro Yamakita
    Proceedings of International Conference on Simulation Technology 1 2014/10 [Refereed]
  • Application of shadow theory to middle regions of multilayered dielectric gratings placed in conical mounting
    Hideaki Wakabayashi; Masamitsu Asai; Keiji Matsumoto; Jiro Yamakita
    Proceedings of International Conference on Simulation Technology 1 2014/10 [Refereed]
  • Hideaki Wakabayashi; Masamitsu Asai; Keiji Matsumoto; Jiro Yamakita
    IEICE TRANSACTIONS ON ELECTRONICS IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG E97C (1) 50 - 57 0916-8524 2014/01 [Refereed]
     
    In the shadow theory, a new description and a physical mean at a low grazing limit of incidence on gratings in the two dimensional scattering problem have been discussed. In this paper, by applying the shadow theory to the three dimensional problem of multilayered dielectric periodic gratings, we formulate the oblique primary excitation and introduce the scattering factors through our analytical method, by use of the matrix eigenvalues. In terms of the scattering factors, the diffraction efficiencies are defined for propagating and evanescent waves with linearly and circularly polarized incident waves. Numerical examples show that when an incident angle becomes low grazing, only specular reflection occurs with the reflection coefficient 1, regardless of the incident polarization. It is newly found that in a circularly polarized incidence case, the same circularly polarized wave as the incident wave is specularly reflected at a low grazing limit.
  • Constitutive characteristics of distributions of conducting helices with helically-bent axes
    M. Asai; H. Wakabayashi; J. Yamakita; K. Matsumoto
    Proceedings of International Conference on Simulation Technology International Conference on Simulation Technology OS13 (1) 55 - 56 2013/09 [Refereed]
     
    螺旋形状の軸をもつ螺旋導体が分布した構造に対する等価媒質特性につき、細線近似モーメント法に準静電的ローレンツ法を組み込む手法を用いて解析し、電気四重極子モーメントの寄与につき明らかにした。
  • Analysis of wave scattering by dielectric gratings for low grazing of circularly-polarized incidence
    H. Wakabayashi; M. Asai; J. Yamakita; K. Matsumoto
    Proceedings of International Conference on Simulation Technology International Conference on Simulation Technology OS13 (1) 13 - 14 2013/09 [Refereed]
     
    誘電体格子に円偏波を低入射角極限で入射した場合の散乱・回折電磁波の解析を影理論に空間高調波展開法を組み込むことにより試みた(英文)。
  • Hideaki Wakabayashi; Masamitsu Asai; Keiji Matsumoto; Jiro Yamakita
    IEICE TRANSACTIONS ON ELECTRONICS IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG E96C (1) 19 - 27 0916-8524 2013/01 [Refereed]
     
    We propose a new analytical method for a composite dielectric grating embedded with conducting strips using scattering factors in the shadow theory. The scattering factor in the shadow theory plays an important role instead of the conventional diffraction amplitude. By specifying the relation between scattering factors and spectral-domain Green's functions, we derive expressions of the Green's functions directly for unit surface electric and magnetic current densities, and apply the spectral Galerkin method to our formulation. From some numerical results, we show that the expressions of the Green's functions are valid, and analyze scattering characteristics by composite gratings.
  • M. Asai; H. Wakabayashi; J. Yamakita; K. Matsumoto
    Materials Integrations T.I.C. 25 (12) 31 - 37 1344-7858 2012/12 [Refereed]
     
    螺旋構造と電磁波の相互作用に関する理論解析手法を提案し、等価媒質特性に占める電気四重極子モーメントの寄与の計算例を示した。
  • Effective constitutive characteristics of racemic mixture of thin-wire helices
    浅居 正充; 若林秀昭; 山; 松本恵治
    Proceedings of International Conference on Simulation Technology OS1 8-1 - 8-4 2012/09 [Refereed]
     
    金属螺旋のラセミ混合体に関する有効媒質特性について検討した。
  • Hideaki Wakabayashi; Keiji Matsumoto; Masamitsu Asai; Jiro Yamakita
    IEICE TRANSACTIONS ON ELECTRONICS IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG E95C (1) 44 - 52 0916-8524 2012/01 [Refereed]
     
    In the scattering problem of periodic gratings, at a low grazing limit of incidence, the incident plane wave is completely cancelled by the reflected wave, and the total wave field vanishes and physically becomes a dark shadow. This problem has received much interest recently. Nakayama et al. have proposed "the shadow theory". The theory was first applied to the diffraction by perfectly conductive gratings as an example, where a new description and a physical mean at a low grazing limit of incidence for the gratings have been discussed. In this paper, the shadow theory is applied to the analyses of multilayered dielectric periodic gratings, and. is shown to be valid on the basis of the behavior of electromagnetic waves through the matrix eigenvalue problem. Then, the representation of field distributions is demonstrated for the cases that the eigenvalues degenerate in the middle regions of multilayered gratings in addition to at a low grazing limit of incidence and some numerical examples are given.
  • Analysis of wave scattering by composite dielectric gratings with conducting strips using scattering factors
    H. Wakabayasi; M. Asai; K. Matsumoto; J. Yamakita
    Proceedings of International Conference on Modeling and Simulation Technology OS5 187 - 192 2011/10 [Refereed]
     
    ストリップ導体を埋設した多層誘電体格子による散乱電磁波の解析を影理論の散乱因子を用いて定式化した。本解析において、各誘電体層内の低入射極限に相当する伝搬波・エバネッセント波に対する特異点を処理を回避することが可能となった。
  • Contributions of the Quadrupole Moments in the Effective Constitutive Characteristics for the Anisotropic Distributions of Metallic Thin-Wire Helices
    M. Asai; H. Wakabayashi; K. Matsumoto; J. Yamakita
    Proceedings of International Conference on Modeling and Simulation Technology OS5 179 - 182 2011/10 [Refereed]
     
    金属細線螺旋の異方性分布に対する等価媒質のの電磁特性に与える電気四重極子モーメントの影響について検討している。
  • Constitutive characteristics of periodic structures composed of coupled metallic helices
    M. Asai; J. Yamakita
    Proceedings of Asia-Pacific Radio Wave Conference Asia-Pacific Radio Wave Conference B4 B4-1 - B4-1 2010/09 [Refereed]
     
    互いに電磁結合した金属螺旋を3次元周期的に配列させた構造の等価媒質特性に
    ついて理論的に検討した。
  • to be written
    M. Asai; J. Yamakita; H. Wakabayashi; K. Matsumoto
    IEICE Transactions C-1 電子情報通信学会 J93-C (3) 81 - 90 2010/04 [Refereed]
     
    誘電体回折格子による散乱電磁界表現に関し、低入射角極限における影現象も含めて
    統一的に表現する手法を提案した。
  • Effective constitutive parameters of periodic structures composed of thin-wire helices
    M. Asai; J. Yamakita
    Proceedings of the International Laser, Light and Microwave Conference T2 24-TP2-4-1 - 24-TP2-4-4 2008/04 [Refereed]
  • Effective Medium Parameters for Distributions of Clustering Helices with Structural Deviations
    M. Asai; J. Yamakita
    Proceedings. of the International Symposium on Antennas and Propagations 1 564 - 567 2007/08 [Refereed]
  • M. Asai
    Memoirs of the School of Biology-Oriented Science and Technology, Kinki University Kinki University 20 (20) 9 - 12 1342-7202 2007 [Refereed]
     
    Effective medium parameters for cluster basis distributions of conducting helices in free space are calculated by quasi-static Lorentz approach combined with the method of moments with thin-wire approximation.
  • Numerical Study on Waves from Particles Composed of Bunches of Helices
    M. Asai; J. Yamakita
    Proceedengs of the Progress of Electromagnetics Research Symposium 1 490 - 490 2006/08 [Refereed]
  • Study on EM waves scattered by chiral or racemic mixture of conducting helices based on thin-wire MoM
    M. Asai
    Memoirs of School of Biology-Oriented Science and Technology of Kinki University No. 16, pp. 29-36 2005 [Refereed]
  • H Wakabayashi; J Yamakita; M Asai; H Inai
    IEICE TRANSACTIONS ON ELECTRONICS IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG E87C (9) 1560 - 1567 0916-8524 2004/09 [Refereed]
     
    The scattering problem by metallic gratings has become one of fundamental problems in electromagnetics. In this paper, a thin metallic grating placed in conical mounting is treated as a lossy dielectric grating expressed by complex permittivity and thickness. The solution of the metallic grating by using the matrix eigenvalue, calculations is compared with that of the plane grating by using the resistive boundary condition and the spectral Galerkin procedure, and the availability of the resistive boundary condition for thin metallic gratings in conical mounting is investigated. In order to improve the convergence of the solutions of thin metallic gratings, the spatial harmonies of flux densities which are continuous function instead of electromagnetic fields are used.
  • to be written
    M. Asai; J. Yamakita; K. Matsumoto; H. Wakabayashi
    Materials Integration 17 (7) 27 - 33 2004/07 [Refereed]
  • M Asai; J Yamakita; H Wakabayashi
    ELECTRICAL ENGINEERING IN JAPAN SCRIPTA TECHNICA-JOHN WILEY & SONS 147 (3) 1 - 8 0424-7760 2004/05 [Refereed]
     
    Diffraction from a uniaxial chiral slab with a two-dimensional periodic array of conducting patches is analyzed by the matrix-based approach. Equatorial anisotropy is assumed for the chirality and permittivity whose optical axis is parallel to the plane of incidence. In the analysis, the total fields are given by the superposition of the current-dependent scattering fields, which are expanded in terms of the two-dimensional space harmonics and the incidence fields. The coupled mode equations for the equatorial uniaxial chiral media give the general solutions of fields as superpositions of elliptically polarized eigenmodes. The unknown currents on the patches are determined by applying the method of moments to the boundary conditions of the conducting array. In the numerical computations, the polarization characteristics of diffracted waves are investigated considering the design parameters. (C) 2004 Wiley Periodicals, Inc.
  • M. Asai
    Memoirs of School of Biology-Oriented Sci.& Tech., Kinki Univ. Kinki University No. 14 (14) 41 - 48 1342-7202 2004 [Refereed]
     
    A matrix-based method of calculations of Green's functions for a one-dimensional periodic distribution of current source embedded in a planar-stratified bianisotropic chiral medium is presented. Numerical examples are given for the cases of a periodic array of thin metallic strips embedded in a bianisotropic chiral medium.
  • Improved convergence in the analysis of thin metallic gratings with thickness profiles
    H. Wakabayasi; M. Komatsu; J. Yamakita; M. Asai
    Radio Science 38 (6) 8-1 - 8-10 2003/08 [Refereed]
  • to be written
    M. Asai; J. Yamakita; H. Wakabayashi
    Transaction of IEE Japan A 123 (3) 239 - 245 2003/03 [Refereed]
  • Masamitsu Asai; Jiro Yamakita; Hideaki Wakabayashi
    IEEJ Transactions on Fundamentals and Materials 123 (3) 239 - 245 1347-5533 2003 [Refereed]
     
    Diffraction from a uniaxial chiral slab with a two-dimensional periodic array of conducting patches is analyzed by the 4 × 4 matrix-based approach. Equitorial anisotropy is assumed for the chirality whose optical axis is parallel to the plane of incidence. In the analysis, the total fields are given by the superposition of the current-dependent scattered fields which are expanded in terms of the two-dimensional space harmonics and the primary fields. The coupled mode equations for the equitorial uniaxial chiral media give the general solutions of fields as the superposition of elliptically-polarized eigen modes. The unknown currents on the patches are determined by applying Moment method to the boundary condition of the conducting array. In the numerical computations, the polarization characteristics of diffracted waves are investigated considering the design parameters. © 2003, The Institute of Electrical Engineers of Japan. All rights reserved.
  • Diffraction from an anisotropic chiral slab with a periodically-apertured plane
    M. Asai; J. Yamakita; H. Wakabayashi
    Proceedings of the Interim International Symposium on Antennas and Propagation 1 21 - 24 2002/11 [Refereed]
  • Diffraction by a periodically-apertured sheet on a uniaxial chiral slab
    M. Asai; J. Yamakita; H. Wakabayashi
    Proceedings of the Asia-Pacific Microwave Conference 3 1533 - 1536 2002/11 [Refereed]
  • Analysis of electromagnetic waves interacting with a planar-stratified bianisotropic medium with a strip grating
    M. Asai; J. Yamakita
    Electromagnetic wave and electronic systems 7 (4) 106 - 111 2002/04 [Refereed]
  • Analysis of electromagnetic waves interacting with planar-stratified bianisotropic media
    M. Asai; J. Yamakita
    Telecommunications and Radio Engineering 58 (1) 154 - 163 2002/01 [Refereed]
  • Use of multilayered step method in analysis of lossless and lossy dielectric gratings
    Hideaki Wakabayashi; Jiro Yamakita; Keiji Matsumoto; Masamitsu Asai
    Proceedings of the International Laser, Lightwave and Microwave Conference 1 89 - 91 2001/11 [Refereed]
  • Electromagnetic Wave Interaction with a Planar-Stratified Bianisotropic Medium with a Strip Grating
    M. Asai; J. Yamakita
    Proceedings of 2001 FESS-MMNA(Russia) 1 12 - 17 2001/08 [Refereed][Invited]
  • Verification of Resistive Boundary of Scattering by a Plane Grating on Multilayered Substrates
    Hideaki Wakabayashi; Jiro Yamakita; Masamitsu Asai; Keiji Matsumoto
    Proceedings of the Progress in Electromagnetics Research Symposium 1 8 - 8 2001/07 [Refereed]
  • Efficient Computation of Dielectric Gratings in Conical Diffraction
    M. Komatsu; J. Yamakita; K. Matsumoto; M. Asai
    Proceedings of 2001 Progress in Electromagnetics Research Symposium 1 7 - 7 2001/07 [Refereed]
  • Plane Wave Scattering from a Thin Metallic Grating in a Planar-Stratified Uniaxial Chiral Medium
    M. Asai; J. Yamakita; H. Wakabayashi; J. Ishii
    Proceedings of 2001 Progress in Electromagnetics Research Symposium 1 386 - 386 2001/07 [Refereed]
  • Plane Wave Diffraction from a Periodic Array of Conducting Patches between Two Uniaxial Chiral Slabs
    M. Asai; J. Yamakita; H. Wakabayashi; J. Ishii
    Proceedings of 2001 Progress in Electromagnetics Research Symposium 1 (1) 13 - 13 2001/07 [Refereed]
  • Masamitsu Asai; Jiro Yamakita; Hideaki Wakabayashi; Junya Ishii
    IEEJ Transactions on Fundamentals and Materials Institute of Electrical Engineers of Japan (IEE Japan) 121 (10) 899 - 904 0385-4205 2001 [Refereed]
  • Efficient improved Fourier-expansion methods for dielectric lamellar gratings in conical diffraction
    M. Komatsu; J. Yamakita; K. Matsumoto; M. Asai
    Proceedings of Japan-China Joint Conf. on Optical fiber science & Electromagnetic Theory 1 87 - 90 2000/12 [Refereed]
  • Analysis of diffracted waves from a uniaxial chiral layer with a thin metallic grating
    M. Asai; J. Yamakita; H. Wakabayashi; J. Ishii
    Proceedings of Japan-China Joint Conf. on Optical fiber Science & Electromagnetic Theory 1 243 - 246 2000/12 [Refereed]
  • Analysis of electromagnetic waves scattered by a uniaxial chiral slab with a thin strip grating
    M. Asai; J. Yamakita; H. Wakabayashi; J. Ishii
    Proceedings of the JSST International Conference on Modeling Cont. and Com. in Simulation 1 333 - 336 2000/10 [Refereed]
  • Analysis of electromagnetic waves diffracted by a grounded uniaxial chiral slab with an infinite array of strips
    M. Asai; J. Yamakita; H. Wakabayashi; J. Ishii
    Proceedings of International Symposium on Antennas & Propagation 1 113 - 116 2000/08 [Refereed]
  • H Wakabayashi; J Yamakita; K Matsumoto; M Asai
    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS SCRIPTA TECHNICA-JOHN WILEY & SONS 82 (12) 38 - 47 8756-663X 1999/12 [Refereed]
     
    The spectral Galerkin procedure is often used for analyzing metallic gratings which are assumed to be zero-thickness plane gratings, In: this report, thin surface relief dielectric gratings with complex permittivity are discussed and analyzed by using the numerical approach for metallic plane gratings with surface impedance. From numerical results for dielectric gratings by the conventional method and metallic plane gratings by the spectral Galerkin procedure, the relations between dielectric and plane gratings are investigated. In addition, some numerical results for infinitely thin gratings with various surface reliefs are given and the differences between surface profiles are investigated. (C) 1999 Scripta Technica.
  • Hideaki Wakabayashi; Jiro Yamakita; Keiji Matsumoto; Masamitsu Asai
    IEICE Transactions C-I The Institute of Electronics, Information and Communication Engineers J82-C-1 (4) 175 - 183 0915-1893 1999/04 [Refereed]
     
    極めて厚みの薄い表面レリーフ形誘電体格子を場所の関数で表される表面インピーダンスをもつ平板格子の計算法を用いて解析できる可能性について示している. 行列固有値による誘電体格子の解析法とスペクトル領域ガレルキン法による平板格子の解析法による数値計算結果の比較から電流展開と抵抗境界条件を適用でき, 平板格子として扱うことができる格子層の厚みについて言及している. 更に, 極めて厚みの薄い誘電体格子について, 格子形状による特性の違いを平板格子の計算法を用いて数値計算を行い, 検討している. 本論文では, 1次元の抵抗格子, リアクタンス格子を扱っている.
  • Analysis of an infinite metallic grating with thickness
    Hideaki Wakabayashi; Jiro Yamakita; Keiji Matsumoto; Masamitsu Asai
    Proceedings of the Progress in Electromagnetics research symposium 2 649 - 649 1999/03 [Refereed]
  • H Wakabayashi; J Yamakita; K Matsumoto; M Asai
    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS SCRIPTA TECHNICA-JOHN WILEY & SONS 80 (12) 7 - 17 8756-663X 1997/12 [Refereed]
     
    The spectral Galerkin procedure is often used to analyze scattering by metallic gratings. The resistive boundary condition is applied to metallic gratings that are assumed to be zero-thickness plane gratings. However, it is difficult to simulate plane gratings without knowing the limits of thickness in the application of such boundary conditions. In this report, the relations between a plane metallic grating and a thin dielectric grating with complex permittivity are investigated by using the conventional method for dielectric gratings. From numerical results, the effectiveness of resistive boundary conditions is discussed. (C) 1998 Scripta Technica.
  • Analysis of electromagnetic waves scattered by strip gratings with isotropic chiral media
    Masamitsu Asai; Jiro Yamakita; Shinnosuke Sawa; Junya. Ishii
    Memoirs of School of Biology-Oriented Science and Technology of Kinki University 2 (2) 24 - 36 1997/10 [Refereed]
  • to be written
    Hideaki Wakabayashi; Jiro Yamakita; Keiji Matsumoto; Masamitsu Asai
    IEICE Transactions C-1 J-80-C-1 (9) 387 - 396 1997/09 [Refereed]
  • J Ishii; J Kodama; S Hontsu; K Murakami; Y Noguchi; M Asai
    SIMULATION IN INDUSTRY: 9TH EUROPEAN SIMULATION SYMPOSIUM 1997 SOC COMPUTER SIMULATION 1 617 - 620 1997 [Refereed]
     
    It is shown in this presentation that RC-thin film circuits composed of lamination by insulators and metallic films are well simulated using nodal analysis of single layered RC distributed lines, giving data base for intelligent simulation,design and methodology of multilayered RC films.
  • M Asai; J Yamakita; S Sawa; J Ishii
    IEICE TRANSACTIONS ON ELECTRONICS IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG E79C (10) 1371 - 1377 1745-1353 1996/10 [Refereed]
     
    4 x 4 matrix-based analysis of electromagnetic waves scattered anisotropic media are presented. In the analysis, the total fields are given as sum of the fields which exist even if the apertured plane are replaced by a ground plane and the fields scattered From the magnetic currents within the apertures. The scattered fields are expanded in terms of two-dimensional Floquet modes. Expression of each fields are obtained through eigenvalue problem for 4 x 4 coupled wave matrix. Unknown magnetic currents in the apertures are determined by applying Galerkin's method to the continuity condition about the magnetic fields in the apertures. Calculated results for isotropic cases are compared with other results for the complementary problem available in the literature using Babinet's principle. Further numerical calculations are performed in the case of gratings with polar-type anisotropic slab.
  • J Ishii; K Murakami; S Hontsu; M Asai
    MODELLING AND SIMULATION 1996 SOC COMPUTER SIMULATION Vol. 10, pp. 17-22 574 - 576 1996 [Refereed]
     
    Multi-coupled wires are formulated in the form of nodal equation allowing to speedy simulation at circuit-level.
  • M ASAI; J YAMAKITA; S SAWA; J ISHII
    IEICE TRANSACTIONS ON ELECTRONICS IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG E78C (10) 1453 - 1459 0916-8524 1995/10 [Refereed]
     
    We present a 4 x 4 matrix-based analysis of scattering from a two-dimensional rectangular resistive plane gratings placed on an anisotropic dielectric slab. The solution procedure used is formulated by extending the 4 x 4 matrix approach[14]. The fields are expanded in terms of two-dimensional Floquet modes. Total fields can be given as sum of primary and secondary fields whose expression are obtained through eigenvalue problem of coupled wave matrix. Unknown currents on resistive patches are determined by applying Galerkin's method to the resistive boundary condition on resistive grating. Results are compared with other numerical examples available in the literature for isotropic cases. Further, numerical calculation are performed in the case of gratings with polar-type anisotropic slab.
  • Electromagnetic field simulation of cable in metallic duct
    J. Ishii; K. Aoki; S. Hontsu; M. Asai
    Proceedings of the 5th European Simulation Congress (3) 17 - 17 1995/09 [Refereed]
  • Scattering by two-dimensional resistive plane gratings with polar-type anisotropic medium
    Masamitsu Asai; Jiro Yamakita; S. Shinnosuke; J. Ishii
    Proceedings of the 5th China-Japan Joint Conference on Optical Fiber Science and Electromagnetic Theory EMT95 (A13) A77 - A82 1995/09 [Refereed]
  • Electromagnetic wave scattering by a two-dimensional plane grating with anisotropic slab
    Electromagnetic wave; scattering by a; wo-dimensional; plane grating with; anisotropic slab
    Proceedings of the IASTED International Conference C-212 249 - 252 1994/09 [Refereed]
  • M ASAI; J YAMAKITA; S SAWA; J ISHII
    IEICE TRANSACTIONS ON COMMUNICATIONS IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG E77B (6) 766 - 769 0916-8516 1994/06 [Refereed]
     
    Electromagnetic power absorption in multilayered tissue media including anisotropic muscle regions whose principal dielectric axes (that is, muscle fibers) have various directions are analyzed by using 4x4 matrix method. Numerical calculations in 10 kHz-10 MHz show the effects of orientation of muscle fibers and polarization of incident wave on absorbed power density in tissues.
  • Akira Ozaki; Masamitsu Asai; Jiro Yamakita; Shinnosuke Sawa
    Electronics and Communications in Japan (Part II: Electronics) 76 (6) 13 - 22 1520-6432 1993 [Refereed]
     
    An analysis and numerical calculation of a leaky wave propagating in a magnetic waveguide with a resistive strip grating are presented. The analysis is formulated by a matrix. A characteristic equation of the waveguide is derived by applying the Galerkin method to a resistive boundary condition expressed by a Green function in a spectrum region for a magnetic material and also by a surface current density which is expanded in terms of functions. A numerical calculation is made for a leaky region where the effect of a surface resistance and magnetic loss are considered. A step function and a function with a singularity are used in expanding a surface current density. The validity of limiting expansion terms and the convergence of solutions are discussed for not only a propagation constant but also a root mean square error of the resistive boundary condition and a surface current density. Copyright © 1993 Wiley Periodicals, Inc., A Wiley Company
  • M ASAI; J YAMAKITA; S SAWA
    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG E75A (12) 1765 - 1767 0916-8508 1992/12 [Refereed]
     
    In this paper, scattering waves by a strip grating with an anisotropic substrate for the incidence of inclined polarization are analyzed, and polarization characteristics of scattered waves are calculated. For simplicity, the analysis is limitted to the case of normal incidence and a perfectly conducting strip grating is assumed.
  • to be written
    Masamitsu Asai; Jiro Yamakita; S. Shinnosuke
    IEICE Transactions C-1 J75-C-I (11) 694 - 702 1992/11 [Refereed]
  • to be written
    Masamitsu Asai; Hikaru Ozaki; Jiro Yamakita; S. Shinnosuke
    IEICE Transactions C-1 J75-C-I (2) 74 - 84 1992/02 [Refereed]
  • Masamitsu Asai; Akira Ozaki; Jiro Yamakita; Shinnosuke Sawa
    Electronics and Communications in Japan (Part II: Electronics) 75 (7) 19 - 31 1520-6432 1992 [Refereed]
     
    This paper analyzes the problem of scattering of a plane electromagnetic wave by a resistive strip grating placed on a multilayered anisotropic substrate. As the method for analysis, the procedures by Teitler and Berreman which can handle the electromagnetic fields in anisotropic medium are extended to which the space harmonic expansion is applied. The currents on the resistive strips are determined by applying Galerkin's method to the resistive boundary condition on the plane with a strip grating. Numerical examples are presented for the reflection coefficients and diffraction efficiencies. First, the results are given in comparison with the data from other publications in the case where the grating is in air or on a grounded dielectric substrate. Afterward, the examples with anisotropic media are presented. Copyright © 1992 Wiley Periodicals, Inc., A Wiley Company
  • On the resistive boundary conditions for planar dielectric structures
    Masamitsu Asai; Jiro Yamakita; S. Shinnosuke
    Bulletin of Osaka Prefecture University Series A 40 (1) 19 - 30 1991/10 [Refereed]
  • to be written
    Masamitsu Asai
    IEICE Transactions C-1 J73-C-I (9) 594 - 596 1990/09 [Refereed]
  • to be written
    Masamitsu Asai
    IEICE Transactions C-1 J71-B (11) 1376 - 1377 1988 [Refereed]

MISC

Books and other publications

  • H. Nakano; M. Asai (Joint work)CORONA Publishing Co. LTD 2012/05 4339008346 161
  • Give and take relationship between life and electronics
    Life; Science Club (Joint workChapter 1)DENKISHOIN CO., LTD 2006 448530017X
  • Inventions and applications of micro-structures giving novel functions
    M. Asai; J. Yamakita; K. Matsumoto; H. Wakabayashi (Joint workPart 2, Chapter 1 , Section 4)TIC CO., LTD 2005 4924890618
  • The leading edge of carbon technology in electronic and medical devices (in Japanese)
    M. Asai; J. Yamakita; K. Matsumoto; H. Wakabayashi (Joint workChapter 1 , Section 7)TIC 2004 4924890677

Courses

  • Foundations of Biological Systems EngineeringFoundations of Biological Systems Engineering Graduate School of Kindai University
  • Laws and Regulations of TelecommunicationsLaws and Regulations of Telecommunications Kindai University
  • An Introduction to Maxwell's EquationsAn Introduction to Maxwell's Equations Kindai University
  • An Introduction to Electromagnetic WavesAn Introduction to Electromagnetic Waves Wakayama University
  • Interdisciplinary Science on Medical Care and Daily LifeInterdisciplinary Science on Medical Care and Daily Life Kindai University
  • Computational Science of Electromagnetic WavesComputational Science of Electromagnetic Waves Graduate School of Kindai University
  • Computer ArchitectureComputer Architecture Kindai University
  • Microwave EngineeringMicrowave Engineering Kindai University
  • Numerical AnalysisNumerical Analysis Kindai University
  • Applied MathematicsApplied Mathematics Kindai University
  • Laws and Regulations of Radio WavesLaws and Regulations of Radio Waves Kyoto University
  • Active CircuitsActive Circuits Kindai University
  • Passive CircuitsPassive Circuits Kindai University
  • ElectromagneticsElectromagnetics Kindai University

Affiliated academic society

  • Optical Society of America   The Marine Inverse Dam Society   Japan Society of Simulation Technology   Radiation Science Society of Japan   The Institute of Electrical and Electronics Engineers (IEEE)   THE INSTITUTE OF ELECTRONICS, INFORMATION AND COMMUNICATION ENGINEERS   THE INSTITUTE OF ELECTRICAL ENGINEERS OF JAPAN   Japan Helical Science Society   

Research Themes

  • 日本学術振興会:科学研究費助成事業
    Date (from‐to) : 1997 -1997 
    Author : 浅居 正充
  • 日本学術振興会:科学研究費助成事業
    Date (from‐to) : 1995 -1995 
    Author : 浅居 正充
     
    無線周波数領域における電磁波の人体に及ぼす影響を考える上で重要となる、多層異方性筋肉を含む人体モデルに対する電力吸収特性の解析を行った。特に、研究代表者が先に行った2次元問題における解析手法や計算結果をふまえ、3次元不均質問題に対する解析手法の定式化及びアルゴリズムの構築、及びそれを用いた電力吸収特性の解析を試みた。その結果、低周波領域で電気的異方性を有する多層筋肉を含み、かつ表面部分に周期性を持つ3次元モデルについて、所期の目的を達成することができた。 1.解析の定式化は、まず散乱界に2次元Floquet Mode展開を施し、4×4行列の固有値問題を介することにより各層の電磁波モードの表現を得た。さらに、変分法に基づく離散化手法を用いることにより、周期性をもつ部分の未知量を決定する線形方程式を導出するプロセスを示した。 2.アルゴリズムの構築に際しては、まず、未知複素振幅ベクトルの基本減衰特性を調べ、オーバーフロー等の数知的な不都合がないように初期値を設定した。つぎに、定式化した理論に完全に対応したアルゴリズムを構築し、各モジュールの動作を確認した。 3.本問題の特別な場合である等方性多層モデル及びその補対なモデルについて数値解析を行い、他文献における計算結果と比較することにより、手法の妥当性を確認した。さらに、解の収束性と種々の計算打ち切り因子との関係を明らかにした。 4.以上の検討に基づき、異方性多層筋肉を含み、かつ表面部分に周期性を持つモデルに対する数値解析を行い、異方性に起因する散乱・回折特性や、それらが電力吸収特性に与える影響等について明らかにした。